Communications devices can communicate with each other via inductive coupling. For example, near field communications (NFC) is a wireless technology based on radio frequency identification (RFID). NFC defines a wireless connection between two devices in close proximity to each other to exchange data between the two devices. For example, the data communications between a reader and a transponder typically are bi-directional and initialed by the reader, which generates a continuous magnetic field. RFID devices that utilize NFC typically can be configured for either passive load modulation (PLM) or active load modulation (ALM).
In a communications device that communicates via inductive coupling, a detuning condition can affect the performance of the communications device. For example, a detuning condition can affect power transfer, shift characteristics (e.g., resonant frequency and Q-factor) of a matching network of the communications device, and the load of the transmitter. However, a typical communications device that communicates via inductive coupling generally does not have a built-in ability to detect the detuning condition.